Cryptwalker I'll imagine that the obvious reasons includes console export?
We've been saying it since Construct Classic was retired though: native feels smoother and runs better on most hardware we've tested than HTML5 + WebGL does (at least right now), and having experienced the porting from C2 to Unity 2D (raycasting) it was confirmed for us again.
This is mostly an argument for CPU-bound games (eg: 2D platformers with lots of raycasting), so effects-wise it's true WebGL *can* do perfectly close to native, but that's also assuming it is supported on the computer it's running on and not black-listed. Meanwhile, every card is pretty much at DirectX 9 compatibility by now.
Also, we have had less hardware and streaming issues with Unity, which has helped us get through Kickstarter so fast because the game works well on almost every computer that has run it so far even with all those fancy shaders and lighting bits we added in (eg: my 2010 business-level laptop can even run it on an old ATI gpu, although we would always recommend higher specs than that for best performance at high resolutions).